DAC improvements slowing down?

better than PBS...

I see mentions of jitter. I believe most jitter on modern DACs is around 2ns and the BBC did studies that said people could not distinguish below 50ns of jitter. Can anyone tell me what jitter sounds like?

Is low jitter like ultra-sonics? Something people can't here but makes things sound better?

Mapman,

Thank you for the clarification. Your explanation matches my understanding. Based on studies done at the beginning of the development of digital sound reproduction jitter was studied and the threshold of jitter was determined. There are no modern DACs that have jitter beyond what people can hear, but yet there is lots of talk about it. So what makes one DAC sound different than another if it is not jitter?

http://downloads.bbc.co.uk/rd/pubs/reports/1974-11.pdf

How are your studies better than the BBC?

I believe you are familiar with Dr. Kiryu's study jitter detection in humans. His findings were that even trained people could detect less jitter than what the BBC reported.

https://www.jstage.jst.go.jp/article/ast/26/1/26_1_50/_pdf

Where are the scientific studies published by any non-marketing organization showing jitter is detectable even in the sub 200ps range?

It doesn't because it can't be done. It is great to develop an ultra-low jitter device for a feat in engineering, but for sound benefits??? I suspect the dust on speaker drivers has a bigger distortion impact than modern day jitter.

Come to think on it - I guess 30 years ago you could have asked the same about Turntables.

Turntable improvements/upgrades/tweaks are more prevalent now than at any time in the past.

I'm not so sure about that... A SME arm, koetsu cart, and an old garrard 301 table would pretty much be a table that can take on many modern top line tables.

The improvement in sound quality will most likely not come from DAC chips. The chips will get smaller and more efficient, but who needs 1024khz/64bit sound, it probably won't happen. The conversion by the chip is pretty set science. However, having said that, improvements will come from the handling of the analog signal and amplification of it after the chip. The old PSU/CAP/linear amp discussion...

Wille,

I suppose so, but I suspect the limit in sound will come from the speakers. The information being fed into the speakers will be much better than that coming from the electronics side.
The next big improvement in digital audio will come from really hi-end DSPs with software that will have potentially infinite band EQ's with both frequency, phase and SPL adjustment. That will be allowed because of the advances in computers. The DAC will just be part of that. In the future all music will be stored digitally (which is really is now).